Liferafts for effecting rescue and support of human life on the high seas are well-known. While early liferafts often took the form of a platform formed of lumber, logs or other floatable materials, more recently liferafts have come generally uniformly to be formed from fabric coated on one or both surfaces with a rubberizing compound and formed into a floatation structure. Typically this floatation structure includes one or more circumferential tubes and a floor. The tubes typically are stacked vertically to form a wall of tubes characterized by an uppermost and lowermost tube and the floor typically is cementingly or vulcanizably adhered to the lowermost tube to preclude the entry of water into the liferaft between the floor and the lowermost tube.
While a basic liferaft is thereby defined, and frequently resembles an inflatable children's swimming pool in appearance, these basic liferaft forms do not, unaltered, find extensive use on high seas. In modern society, regulations, legislation, and practice in many countries of the world require such basic rafts to include other features.
Typically today, such liferafts include an insulation means the better to separate occupants of the raft from cold waters surrounding the raft by more than simply a single ply layer of rubberized fabric. So, modern liferafts typically have a double-walled bottom inflated to provide an insulation capability or where liferafts have a single ply bottom, these liferafts will also include a plurality of insulating floor sections that typically include an insulation pad formed of an insulating material such as foam.
Liferafts today may also include a canopy configured to provide a sheltering roof over the raft thereby at least partially protecting occupants of the raft from wind and wave. Typically these canopies include a center support within the raft configured to hold the canopy over the heads of occupants of the raft without the necessity for the occupants jointly raising arms to physically hold the canopy in place above their heads.
Liferafts today may also include an inflatable boarding ramp affixed by vulcanization or cementation to an external surface of the raft, functioning to facilitate boarding from deep, open waters. In addition, liferafts today typically include at least one ballast means. These ballast means tend to lower the center of gravity of the liferaft and thereby reduce a tendency for the liferaft to tip over and/or tumble during conditions of strong waves and high winds.
It is the custom for liferafts to be formed as an integral unit; that is all, or nearly all of the necessary units of the raft subject to deterioration and/or failure have generally been co-attached permanently so that repair of one or more portions of the raft and its accessories can be quite difficult. Often unrepairable damage to one accessory can render the entire liferaft unuseable necessitating replacement. A liferaft in which one of the various components could, upon failure or damage, be removed and replaced while necessary repairs to the component are undertaken, could find substantial utility in commerce.